diff --git a/crates/anthropic/src/anthropic.rs b/crates/anthropic/src/anthropic.rs
index 28e306d314..1dd447a1c9 100644
--- a/crates/anthropic/src/anthropic.rs
+++ b/crates/anthropic/src/anthropic.rs
@@ -148,8 +148,13 @@ impl Model {
         }
     }
 
+    pub const DEFAULT_BETA_HEADERS: &[&str] = &["prompt-caching-2024-07-31"];
+
     pub fn beta_headers(&self) -> String {
-        let mut headers = vec!["prompt-caching-2024-07-31".to_string()];
+        let mut headers = Self::DEFAULT_BETA_HEADERS
+            .into_iter()
+            .map(|header| header.to_string())
+            .collect::<Vec<_>>();
 
         if let Self::Custom {
             extra_beta_headers, ..
@@ -186,12 +191,14 @@ pub async fn complete(
     request: Request,
 ) -> Result<Response, AnthropicError> {
     let uri = format!("{api_url}/v1/messages");
-    let model = Model::from_id(&request.model)?;
+    let beta_headers = Model::from_id(&request.model)
+        .map(|model| model.beta_headers())
+        .unwrap_or_else(|_err| Model::DEFAULT_BETA_HEADERS.join(","));
     let request_builder = HttpRequest::builder()
         .method(Method::POST)
         .uri(uri)
         .header("Anthropic-Version", "2023-06-01")
-        .header("Anthropic-Beta", model.beta_headers())
+        .header("Anthropic-Beta", beta_headers)
         .header("X-Api-Key", api_key)
         .header("Content-Type", "application/json");
 
@@ -302,12 +309,14 @@ pub async fn stream_completion_with_rate_limit_info(
         stream: true,
     };
     let uri = format!("{api_url}/v1/messages");
-    let model = Model::from_id(&request.base.model)?;
+    let beta_headers = Model::from_id(&request.base.model)
+        .map(|model| model.beta_headers())
+        .unwrap_or_else(|_err| Model::DEFAULT_BETA_HEADERS.join(","));
     let request_builder = HttpRequest::builder()
         .method(Method::POST)
         .uri(uri)
         .header("Anthropic-Version", "2023-06-01")
-        .header("Anthropic-Beta", model.beta_headers())
+        .header("Anthropic-Beta", beta_headers)
         .header("X-Api-Key", api_key)
         .header("Content-Type", "application/json");
     let serialized_request =